Dose indicator devices are well known, and can include either counters, displaying a number corresponding to the number of doses that have been dispensed or that remain to be dispensed, or indicators, informing the user by means of symbols, color codes, or similar numbers, about the number of doses that have been dispensed or that remain to be dispensed. In particular, in fluid dispensers containing pharmaceuticals, it is important for the dose indicator device to function in reliable manner, and in particular for it to count the dispensing of a dose each time the fluid is dispensed, regardless of whether the dose is complete or incomplete, e.g. because of accidental actuation or actuation that is interrupted before the end of the actuation cycle. It is generally preferable for the dispensing of an incomplete dose to be counted as a complete dose rather than for it not to be counted at all, since failure to count could present a high risk to the user, informing the user of a reservoir content that is greater than the reality. In dispensers of pharmaceuticals, it is thus generally desirable to avoid any risk of under-counting, in particular by triggering counting just before the active substance is expelled. Another important point with dose indicator devices for dispensers of pharmaceuticals is that once actuation has taken place and a dose has been dispensed, while the dispenser is returning to its rest position, any further actuation that is performed before the end of the return stroke of the dispenser, and that would cause a complete or incomplete dose to be dispensed, should also be counted by the indicator device, likewise to avoid any risk of under-counting. In most fluid dispensers, once a dose has been dispensed, the next dose is loaded into the chamber of the dispenser member (pump or valve) while the dispenser is returning to its rest position. In order to avoid any risk of under-counting during the return stroke of the dispenser, it is desirable for the fluid dispenser to be blocked as soon as the return stroke has allowed the chamber to be filled, and until the indicator device is once again able to count the actuation of the dispenser.